Field of the Invention
The present invention relates to an electrophotographic photosensitive member, and a process cartridge and an electrophotographic apparatus including an electrophotographic photosensitive member.
Description of the Related Art
An electrophotographic photosensitive member containing an organic photoconductive material (charge generation material) is used as an electrophotographic photosensitive member to be mounted on a process cartridge and/or an electrophotographic apparatus. A common electrophotographic photosensitive member includes a support and a photosensitive layer formed on the support, the photosensitive layer containing a charge generation material.
Furthermore, an undercoat layer is often provided between the support and the photosensitive layer for the purpose of suppressing charge injection from the support to the photosensitive layer.
In recent years, charge generation materials having a higher sensitivity have been used. Along with an increase in sensitivity of the charge generation material, however, the amount of a charge to be generated is larger, and therefore the charge is easily retained in the photosensitive layer to easily cause positive ghost to occur. The positive ghost is a phenomenon where the density of only a region irradiated with light in pre-rotation during formation of one sheet of an image is increased.
As a technique for suppression of such positive ghost, Japanese Patent Application Laid-Open No. 2007-148294 and Japanese Patent Application Laid-Open No. 2008-250082 describe a technique in which an electron transport material is contained in an undercoat layer. Japanese Patent Application Laid-Open No. 2007-148294 and Japanese Patent Application Laid-Open No. 2008-250082 also describe a technique in which, when the electron transport material is contained in the undercoat layer, the undercoat layer is cured so as not to, during formation of an upper layer (photosensitive layer) of the undercoat layer, elute the electron transport material into a solvent in a coating liquid for a photosensitive layer.